Although pretty new to cosplay photography (I've only had 3 photoshoots), I was obsessed with modeling for a few years so I've come up with a few things to keep in mind that help people look good in pictures.

Your face
Let's start with the basic and (in my opinion the most make-or-break) part of photos.

Your eyes

1. One of the first things to keep in mind is that if you're supposed to be looking at someone close up, do not actually look at them. Doing such will make you look cross-eyed. Instead, look past them.

2. Avoid the 'deer-in-headlights' look, unless that's in character. Keep your eyes relaxed. If you want to avoid looking like your eyes are closed, look up. It will naturally make you open your eyes slightly.

3. Narrowing your eyes very slightly will help you look focused rather than like you're dazed. It can also reflect passion/anger/ect without making you furrow your brows or something.

5. A smile looks more real if you squint your eyes slightly. However, tilting your chin down and looking slightly up at the camera will make you look a bit devious.

Your mouth

1. If you're trying to portray a soft character or a soft emotion, part your lips very slightly and only in the middle.

2. If you're trying to portray a hard/strong character or an intense emotion, keep your lips together.

3. If you're trying to give a very small smile, bite the insides of your cheeks while you smile. It will keep you from reflexively smiling too wide.

Overall

1. Think beyond looking straight at the camera. If you want to look at the camera, you can look with your eyes while turning your head slightly, or tilting it (either up or down), or a combination of both. I suggest looking at the mirror and pairing different expressions and head positions to see what they look like together.

2. Try to keep some sort of tension in your face. Don't just be blank. Even with deadpan characters, do something very subtle with your face.

I hope I helped in some way, and I'm in no way criticizing anyone who does things differently. These tips are guidelines and not rules, so there are things I may be wrong with. These are just things that I find useful.

EDIT:
"And remember, GUYS, don't be above makeup for photoshoots. Even the toughest bad@$$ in the movies wear it."
-tfcreate

This is more of an overall appearance tip than a modeling one.
Why should you wear makeup for photoshoots?
Plenty of reasons:

1. Wearing foundation/concealer ect will keep you looking awake (when used under the eyes), keep you from looking red, make your skin look smoother, ect. Speaking at least for anime and manga, this will most likely make you look more like the character.

2. It will bring out features that might be lost with bright lights, editing, ect. For example, my eyebrows aren't very thin, so I thought I could go without darkening them (my character and I had the same eyebrow color). The guy I was posing with was in the same situation, but darkened them anyway. After the photographer edited the lighting, I ended up having teeny tiny eyebrows that almost disappeared. My friend's eyebrows looked fine.

On the subject of moister, stay hydrated. The heat will just drain you and it will show in your face so keep water or sports drinks (watch out with some of the dyes unless a blue tongue fits your character) handy.

If you can swing-it carry some blotting sheets if you tend to have oily skin. It can be fixed in Photoshop but most photographers donít bother. If you can carry a small mirror that will also help make sure everything is as it should be.

After the shot, ask to look at the picture. Donít worry if itís a little dark or bright thatís easily fixed but look at yourself and how the overall composition looks AND REALLY LOOK AT IT! This is your opportunity to collaborate with the photographer so step-up and take the time to look at what might be posted for all the world to see. If it doesnít look right to you then ask for a do-over. I canít speak for all photographers but imo any photographer worth his/her salt will only want to present the best shot(s).

And remember, GUYS, don't be above makeup for photoshoots. Even the toughest bad@$$ in the movies wear it.

__________________~A fool can learn from his own mistakes..The wise learn from the mistakes of others.~ Democritus It's pointless to brag about equipment.Repeat what you see in my posts and you'll sound really smart

Rules for life: Rule #7 Before you were born, your parents weren't as boring as they are now. They got that way from paying your bills, cleaning your clothes and listening to you talk about how cool you are. Anime MidwestAnime Chicago Chicago ComiconAnime Iowa

And remember, GUYS, don't be above makeup for photoshoots. Even the toughest bad@$$ in the movies wear it.

Can I like this a thousand times?
We mean no offense to you or your face. It overall will help you get the look you want. (Although I'm not saying that you should whip out false eyelashes and lip color when your character is a masculine guy)

Totally agree with the makeup tip, even a soft eyeshadow to match your cosplay for female characters goes a long way and it helps not being washed out by bright colors. When I do Madame Red or Eternal Sailor Moon make up is a super must for me because the colors completely wash me out but some color here and there really make my face more balanced with my outfits and makes it look more finished. Also if you live in warm climates like I do in Florida it will help not make it seem like you ran a marathon before a photo with sweat

I actually need help-I'm going to be doing Vanessa from Luminous Arc, and as a character, she's a bit flirty. I need help with posing with winks and maybe even blowing a few kisses. I've been doing photoshoots with a friend but I've never had any practice with these kinds of faces, as my characters are usually very stoic and have serious faces. This is my first 'fun' character, and I want to widen my range of emotion when doing the modeling. Does anyone have any tips for these two in particular?

I actually need help-I'm going to be doing Vanessa from Luminous Arc, and as a character, she's a bit flirty. I need help with posing with winks and maybe even blowing a few kisses. I've been doing photoshoots with a friend but I've never had any practice with these kinds of faces, as my characters are usually very stoic and have serious faces. This is my first 'fun' character, and I want to widen my range of emotion when doing the modeling. Does anyone have any tips for these two in particular?

First off, don't be afraid to go out there! It's better to be overdoing it than to be subdued. Can you lift one eyebrow at a time? You could try lifting one and pouting your lips. If you wink, really focus on keeping your other eye open.

This is so helpful! I have really squinty eyes when I smile so the technique that you said about looking up slightly makes perfect sense when my friend and I do a photoshoot we will test this out X3 Thank you!

any tips on girls who have kind of ...chubby cheeks? i dont know what the term would be. but when i smile i have lines around my mouth because of my cheeks. how should i work around this problem? i dont like looking at my pictures and seeing only the lines on my face! rawrrawrrawr!

and they arnt laugh lines. im not quite old enough for that and they arnt there permanently

Thank you for the tips! Do you have any advice for not looking angry? XD I always do without trying to! @-@

I do that, too--or else, I look like I'm pouting about something. I've learned to try to relax my face as much as possible--since my "neutral face" is apparently a little frowny, I'll try to think about something pleasant, smooth out my forehead as much as possible, open my eyes a bit wider than natural, and put on the barest hint of a smile--it won't come out as a smile, so much as just "not a pout".

I do that, too--or else, I look like I'm pouting about something. I've learned to try to relax my face as much as possible--since my "neutral face" is apparently a little frowny, I'll try to think about something pleasant, smooth out my forehead as much as possible, open my eyes a bit wider than natural, and put on the barest hint of a smile--it won't come out as a smile, so much as just "not a pout".